Wei,

On my web site I have two classes for sending HTTP requests (GET, POST and others). They rely respectively on WinINet and WinHTTP API libraries.

Custom HttpRequest class (WinHTTP)
http://www.news2news.com/vfp/?example=397

Custom HttpRequest class (WinINet)
http://www.news2news.com/vfp/?example=185

WinINet exists virtually on every Windows computer. WinHTTP is not supported on Win95/98/Me systems and this way is somehow limited.

* * *
Another option is using Microsoft ServerXMLHTTP object:

oHttp = CreateObject("MSXML2.ServerXMLHTTP")

It works great, out of the box, and has plenty of useful functionality. Though same way as WinHTTP it's limited to newer systems: XP/2K/2003. And of course, you have to install it to use.